In the text below reference is made to the following prior art documents:    (1) Carter, A. D. Weed Res., 2000, 40, 113-122.    (2) Motzer, W. E. Environmental Forensics 2001, 2, 301-311.    (3) Urbansky, E. T. Environ. Sci. & Pollut. Res., 2002, 9, 187-192.    (4) Lagaly, G. In: Proc. of the 10th International Clay ConferencSurface and interlayer reactions. Churchman, G. J., Fitzpatrick, R. W. & Egglegton, R. A. Eds.; CSIRO Pub.: Melbourne, Australia, 1995; pp. 137-144.    (5) Xu, S.; Sheng, G.; Boyd, S. A. Adv. Agron. 1997, 59, 25-62.    (6) Mishael, Y. G.; Undabeytia, T.; Rytwo, G.; Papahadjopoulos-Sternberg, B. Rubin, B.; Nir, S. J. Agric. Food Chem. 2002, 50, 2856-2863.    (7) Polubesova, T.; Nir, S.; Zadaka, D.; Rabinovitz, O.; Serban, C.; Groisman, L.; Rubin, B. Environ. Sci. Technol. 2005, 39, 2343-2348.    (8) Polubesova, T.; Zadaka, D.; Groisman, L.; Nir, S. Water Res. 2006, 40, 2369-2374.    (9) Nir, S.; Zadaka-Amir, D.; Kartaginer, A.; Gonen. Y. Appl. Clay Sci. 2012, 67-68, 134-140.    (10) U.S. Pat. No. 8,361,325, Method and system for removal of inorganic pollutants from contaminated water. Inventors: Shlomo Nir (Mazkeret Batya, Ill.)    (11) Bitton, G. Wastewater Microbiology. New York: Wiley-Liss, 1994.    (12) Hwang, B; Mangus, P; Jaakkola J. J. K. Amer J Epidemiol. 2002; 156, 374-382.    (13) Knappett, P S K, Emelko M B, Zhuang J, McKay L D. Wat Res 2008; 42:4368-4378.
These prior art documents are relevant for understanding the state of the art in the field of the invention. The references will be referred to in the text by giving their serial numbers from said list. Whereas granulation of substances in the pharmaceutical industry is well established, the intended use of micelle-clay granules for optimal removal of chemicals and microorganisms from water required the determination of a particular procedure with a narrow range of conditions.
Pollution of groundwater and wells has become an environmental and economical hazard due to intensively irrigated agriculture and application of herbicides and pesticides over cultivated lands as well as waste spills within the catchment areas of the various hydrogeological basins (1).
Perchlorate anion (ClO4−), which is quite inert, is produced when salts of ammonium, or sodium perchlorate dissolve in water. One source of perchlorate in water arises from waste water of plants of solid rocket engine fuels. Another source is due to the use of certain fertilizers. At relatively large concentrations, perchlorate interferes with the body's iodine intake, causing disruption of thyroid gland functions (2, 3), although a safe daily exposure has not yet been agreed upon. Upper limits on perchlorate concentrations in drinking water in several states in USA (and Israel) vary between a few ppb and about twenty ppb. Regions in aquifers with perchlorate concentrations at 1000-fold higher than the above limit have been identified.
The adsorption of organic cations on clays partially transforms the clay-mineral surface from hydrophilic to hydrophobic (4, 5). The micelle-clay system is a relatively new innovation in which the structure includes a positively charged surface to a varying degree and a hydrophobic core (6,7). These characteristics were utilized in removing several organic pollutants (8,9) and in a patent (10) for removal of inorganic anionic pollutants, such as perchlorate from water.
One concern regarding water quality is minimizing the concentration of pathogenic microorganisms in water, thereby reducing the risk of an outbreak of waterborne diseases in humans or animals. A wide variety of enteric microbial pathogens may be found in wastewater (11). A number of bacterial pathogens which cause diseases such as dysentery, typhoid, and gastroenteritis have been transmitted primarily through untreated sewage irrigated vegetables.
Chlorination has been the main strategy for the disinfection of drinking water and wastewater, by inactivating pathogenic microorganisms. Alternative technologies have been evaluated because of the increasing concern over undesirable production of trihalomethanes (THMs), due to chlorination at high doses, whereas reduced efficiency in eliminating some epidemic microorganisms occurs at low doses (12).
Alternative means of disinfection include chloramines, chlorine dioxides, ozone and ultraviolet radiation, which also have several major disadvantages, such as the formation of carcinogenic by-products, residuals in treated water and reactivation of microorganisms after exposure. Since an ideal disinfection technique has not yet been found, combinations of several techniques are being used (12).
Enteric bacteria, viruses and protozoan parasites carry a negative surface charge (Knappett et al. 2008 13). Therefore, the system of positively charged micelle-clay complexes may be useful for the removal of organic pollutants and pathogenic microorganisms from water.
Filtration is the major procedure for removal of pollutants by adsorption. In order to enable flow in a filter, which includes a micelle-clay complex in powdered form it is needed to mix the complex with excess of granular material, such as sand, generally at a ratio of at least 19:1 w/w. This implies that such a filter includes just 5% of active ingredient, which necessitates frequent replacements. The present invention of granulation of the micelle-clay complex enables a free flow in a filter which includes exclusively the active ingredient.